A display device is provided that includes a panel driving circuit configured to control the power supply unit to be disabled in response to a low-power mode and adjust a length of time required for a voltage level applied to high-potential voltage lines to transition from a first high-potential voltage to a second high-potential voltage. Thus, it is possible to suppress display of an abnormal image on a display panel in the low-power mode, and a length of time for transitioning from the normal mode to the low-power mode can be adjusted, and, thus, the brightness of the display panel can be naturally changed.